But, apparently, that wasn't enough for one of UK's top agencies. According to Nelson, the unnamed company told her that she was perfect in every regard — except she needed to lose weight.

So Nelson did just that, and four months later returned about 14 pounds lighter and with two inches off her hips. But the agency said she had to lose even more weight; it wanted her "down to the bone."

"When I look in the mirror I see someone that is healthy and comfortable in their skin," she wrote in the Change.org petition.

"That's because I had the guts to carve out my own path and refuse to let people pressure me into losing more and more weight. ... Modeling can be a very lonely place, especially for girls working internationally who are away from the usual support network of friends and family. When models travel overseas they are often put into shared accommodation with other models, and being surrounded by girls who are all striving to stay thin can perpetuate bad eating habits and encourage eating disorders. I've been on shoots for up to 10 hours where no food is provided — the underlying message is always that you shouldn't eat."

And people are responding — the petition now has more than 50,000 signatures.

Nelson's petition points to France's legislation from earlier this year that bans fashion agencies from hiring excessively skinny models. Those who break the law could face jail time and a large fine.

It also acknowledges a growing shift in the UK towards legal protection for models' health. "Caroline Nokes MP is the Chair of the All Party Parliamentary Group on Body Image and is campaigning for the Government to look at the possibility of legislating to ensure models are of a healthy weight," Nelson wrote. " The time is now for us all to come together."

And if Nelson succeeds, we'll be looking forward to seeing healthy, glowing models on the runway next year.